The present invention relates to an automotive air bag device and, more particularly, to an automotive air bag device wherein the air bag inflation opening is formed in an automotive panel such as an instrument panel or a door panel, and this opening is covered with an air bag lid.
Referring to FIG. 4, there is shown a conventional passenger-side automotive air bag device 2 disposed in an automobile instrument panel 1. In the illustration, air bag 2 device is installed at an angle that allows it to be easily viewed in the drawing. This does not necessarily correspond to actual installation angles.
Instrument panel 1 is formed of a two-layer material including a core material 1a and a surface material 1b. A rectangular air bag inflation opening 1c is formed at a prescribed position on instrument panel 1.
Air bag device 2 includes a semi-cylindrical metal case 4 fixed to a vehicle body via a bracket 3. An inflator 5, housed in case 4, inflates an air bag 6 when inflator 5 is activated. A metal guide member 8 is fixed to case 4 by a plurality of mechanical fasteners 7,7 (only two are shown). An air bag lid 10 is fixed to guide member 8 by a plurality of mechanical fasteners 9,9 (only two are shown). These elements are assembled to the vehicle body as a single unit.
Air bag lid 10 covers opening 1c of instrument panel 1. Air bag lid 10 includes a main lid unit 10b having a scoreline 10a. Legs 10c, projecting from the back surface of main lid unit 10b, are fastened to guide member 8 so as to retain lid 10 when air bag 6 inflates.
In air bag device 2, bracket 3, case 4, inflator 5, air bag 6, guide member 8, and air bag lid 10 comprise a subassembly. When installing this subassembly in the vehicle body, the proper alignment of air bag lid 10 with opening 1c is difficult to achieve. Proper alignment requires the edges of opening 1c and the outer edges of air bag lid 10 be aligned both along the plane of the opening and along the depth axis, i.e. alignment must be performed in three dimensions. If perfect alignment is not achieved, the cosmetic appearance of instrument panel 1 will suffer.
Furthermore, the inclusion of guide member 8, which maintains subassembly integrity when air bag 10 inflates, increases the size of air bag device 2, thus making the alignment operation described above even more difficult. Finally, the subassembly includes a substantial number of parts, so that material and assembly costs are high.